How to reduce polygon of a wire model
Maybe Skin is not the best tool to build your mesh, anyway there is a efficient way to simplify a mesh:


In Edit / Edge Selection mode, select an edge ring with ctrl alt right click.
Got to Select > Checker Deselect. Now only one of two edges is selected (or even less if you want, play with the factors at the bottom of the T menu, on the left of the 3D view).
Go to Select > Edge Loops. Now the edge loops of these edges are selected.
Delete these edge loops with X > Edge Loops